1. Field of the Invention
The present invention relates to a head-mounted picture display device. More particularly, this invention is concerned with a head-mounted picture display device having a picture display system. The picture display system includes picture display members for producing pictures represented by a supplied picture signal, and prisms for introducing beams which transmit the pictures produced by the picture display members to the observer""s eyes.
2. Description of the Related Art
In recent years, various head-mounted picture display devices including a head-mounted display (HMD) have been proposed as compact display devices for displaying a picture and transmitting sound associated with the picture, and put to practical use generally. The compact display devices are used to view pictures or to play various kinds of games.
The head-mounted picture display device (hereinafter referred to as a HMD) is generally composed of a picture display system, a housing body, and supporting members. The picture display system includes compact liquid crystal displays (hereinafter LCDs) formed with display elements for visualizing pictures, and an optical system including prisms for projecting pictures produced by the LCDs onto the user""s retinas. Drive circuits for driving the LCDs are incorporated in the housing body. The supporting members are included for supporting the housing body on the front side of the user""s head.
Generally, frames are structured to have bows attached to the left and right edges of a front frame in which lenses are mounted, so as to be able to pivot freely. The bows are placed on the observer""s ears, whereby the lenses can be retained in front of the eyes.
An example of such frames has been described in, for example, Japanese Unexamined Patent Publication No. 8-62546. Specifically, V-shaped slits opening inward are formed at the left and right edges of a front frame in which lenses are mounted. Cylindrical concave parts are extending in the bottoms of the V-shaped slits. Cylindrical pin members attached to the ends of the left and right bows are press-fitted in the cylindrical concave parts so that the pin members can be removed freely. The patent publication discloses that a polycarbonate resin is used to make the frames.
The foregoing head-mounted picture display device has been made to be lightweight in recent years. Accordingly, proposals have been made for a head-mounted picture display device in which supporting frames shaped analogously to the bows of the frames are employed and a housing body accommodating the picture display system is borne by the observer""s head.
However, the aforesaid HMD proposed in the past is generally designed to be worn so as to partly mask the user""s face.
The thus designed HMD, that is, the HMD which is worn so as to partly mask the user""s face will be discussed briefly. When a user wears the HMD to view a picture or the like, supporting members press against the user""s head. The user will therefore feel the exertion of pressure. If the HMD is worn over a prolonged period of time, it may make the user uncomfortable.
Moreover, in an HMD having supporting members designed to mask a large portion of the user""s head and face, the weight of the supporting members themselves is increased. If various functions are to be included, components for realizing such functions must be added. This leads to an additional increase in the weight of the HMD itself. Discomfort attributed to a user wearing the HMD will thus further increase.
The aforesaid head-mounted picture display device is, unlike the aforesaid frames that should be sized to fit a specific user, used by a plurality of observers whose heads are of various sizes. Supporting frames for supporting the HMD can preferably withstand a wide range of stresses and readily exhibit a spring force. The polycarbonate resin described as the material used to make the frames in Japanese Unexamined Patent Publication No. 8-62546 is not fully satisfactory from this standpoint.
Many users of the HMD use hair treatment agents. The hair treatment agents contain various chemicals. Among the chemicals, for example, alcohol may reportedly cause a resin to deteriorate. The supporting frames are members typically exposed to a user""s hair. The chemicals often adhere to the supporting frames. The supporting frames must therefore be made to resist the chemicals. As far as the polycarbonate resin is concerned, when stress is exerted thereon by user contact after being exposed to the chemicals, it tends to deteriorate with the passage of time and then break abruptly. From this standpoint also, the polycarbonate resin is not fully satisfactory.
The first object of the present invention is to provide a compact and lightweight head-mounted picture display device.
The second object of the present invention is to provide a head-mounted picture display that is comfortably worn.
The third object of the present invention is to provide a head-mounted picture display device offering excellent maneuverability.
The fourth object of the present invention is to provide a head-mounted picture display device in which various functional units are simplified in order to improve wearing comfort, realize a compact and lightweight design, and offer excellent maneuverability.
The fifth object of the present invention is to provide a head-mounted picture display device which can be exchangeable among observers whose head sizes fall within a wide range.
The sixth object of the present invention is to provide a highly reliable head-mounted picture display device that is chemical-resistant.
The seventh object of the present invention is to provide a highly reliable head-mounted picture display device that is exchangeable among observers whose head sizes fall within a wide range due to its elasticity, and is also chemical-resistant.
Briefly, the present invention provides a head-mounted display picture display device comprising a picture display system, a housing body, left and right supporting frames, and joint members. The picture display system includes picture display members for producing pictures represented by a supplied video signal and prisms for introducing beams which transmit the pictures produced by the picture display members to the observer""s eyes. The housing body accommodates the picture display system. The left and right supporting frames are put on the observer""s left and right ears, thus supporting the housing body in an observable posture. The joint members link the housing body and the left and right supporting frames. The housing body is realized by joining a back housing body and a front housing body. The back housing body occupies a position relatively close to the observer""s face with the display device mounted on the observer""s head. The front housing body occupies a position relatively away from the observer""s face with the display device mounted on the observer""s head. The upper and lower parts of the joined surfaces of the back and front housing bodies with respect to apertures in which the joint members are fitted are displaced from each other in terms of their back-to-front positions.
These objects and advantages of the present invention will become further apparent from the following detailed explanation.